Japan safety agency: roof cracked at Fukushima No 4 reactor

TOKYO, March 16 (Reuters) - Two workers are missing after
Tuesday's explosion at one of the reactors at a crippled
Japanese nuclear plant, the country's nuclear saftey agency
said.

The agency did not identify the missing workers, but said
they were in the turbine area of the No.4 reactor at the
Fukushima nuclear plant, which was damaged by last Friday's
earthquake and tsunami.

Agency official also told a news conference there was a
crack in the roof of the reactor building.

Authorities are desperately trying to prevent the water
which is designed to cool the radioactive cores of the plant's
reactors from running dry, which would lead to overheating and
the release of dangerous radioactive material into the
atmosphere.

It was possible the water in the reactor was boiling, the
agency said.
(Reporting by Terril Jones)